<!DOCTYPE html>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>原生JS实现购物车结算功能代码</title>
    <link rel="stylesheet" href="../css/style.css" />
</head>

<body>
    <div class="catbox">
        <table id="cartTable">
            <thead>
                <tr>
                    <th><label>
                            <input class="check-all check" type="checkbox" />&nbsp;&nbsp;全选</label></th>
                    <th>商品</th>
                    <th>单价</th>
                    <th>数量</th>
                    <th>小计</th>
                    <th>操作</th>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td class="checkbox"><input class="check-one check" type="checkbox" /></td>
                    <td class="goods"><img src="../images/1.jpg" alt="" /><span>Casio/卡西欧 EX-TR350</span></td>
                    <td class="price">5999.88</td>
                    <td class="count"><span class="reduce"></span>
                        <input class="count-input" type="text" value="1" />
                        <span class="add">+</span>
                    </td>
                    <td class="subtotal">5999.88</td>
                    <td class="operation"><span class="delete">删除</span></td>
                </tr>
                <tr>
                    <td class="checkbox"><input class="check-one check" type="checkbox" /></td>
                    <td class="goods"><img src="../images/2.jpg" alt="" /><span>Canon/佳能 PowerShot SX50 HS</span></td>
                    <td class="price">3888.50</td>
                    <td class="count"><span class="reduce"></span>
                        <input class="count-input" type="text" value="1" />
                        <span class="add">+</span>
                    </td>
                    <td class="subtotal">3888.50</td>
                    <td class="operation"><span class="delete">删除</span></td>
                </tr>
                <tr>
                    <td class="checkbox"><input class="check-one check" type="checkbox" /></td>
                    <td class="goods"><img src="../images/3.jpg" alt="" /><span>Sony/索尼 DSC-WX300</span></td>
                    <td class="price">1428.50</td>
                    <td class="count"><span class="reduce"></span>
                        <input class="count-input" type="text" value="1" />
                        <span class="add">+</span>
                    </td>
                    <td class="subtotal">1428.50</td>
                    <td class="operation"><span class="delete">删除</span></td>
                </tr>
                <tr>
                    <td class="checkbox"><input class="check-one check" type="checkbox" /></td>
                    <td class="goods"><img src="../images/4.jpg" alt="" /><span>Fujifilm/富士 instax mini 25</span></td>
                    <td class="price">640.60</td>
                    <td class="count"><span class="reduce"></span>
                        <input class="count-input" type="text" value="1" />
                        <span class="add">+</span>
                    </td>
                    <td class="subtotal">640.60</td>
                    <td class="operation"><span class="delete">删除</span></td>
                </tr>
            </tbody>
        </table>
        <div class="foot" id="foot">

            <a class="fl" id="deleteAll" href="javascript:;">删除</a>
            <div class="fr closing" onclick="getTotal();">结 算</div>
            <input type="hidden" id="cartTotalPrice" />
            <div class="fr total">合计：￥<span id="priceTotal">0.00</span></div>
            <div class="fr selected" id="selected">已选商品<span id="selectedTotal">0</span>件<span
                    class="arrow up">︽</span><span class="arrow down">︾</span></div>
            <div class="selected-view">
                <div id="selectedViewList" class="clearfix">
                    <div><img src="../images/1.jpg"><span>取消选择</span></div>
                </div>
                <span class="arrow">◆<span>◆</span></span>
            </div>
        </div>
    </div>
</body>
<script>

    // 全选功能:
    // 单击全选 所有的单选 跟随全选的状态

    // 反选功能:
    // 每次点击单选 => 判断所有的单选(商品)是否全部被选中, 如果全部选中 => 全选(反选)  否则 => 全选(取消反选)


    var checkAll = document.getElementsByClassName("check-all")[0];
    var checkOneList = document.getElementsByClassName("check-one");


    // 全选: 
    // 单击全选 所有的单选 跟随全选的状态
    checkAll.onclick = function () {
        var status = this.checked;
        console.log(status);

        for (var i = 0; i < checkOneList.length; i++) {
            var checkOne = checkOneList[i];
            checkOne.checked = status;
        }
    }


    // 反选功能:
    // 每次点击单选 => 判断所有的单选(商品)是否全部被选中, 如果全部选中 => 全选(反选)  否则 => 全选(取消反选)

    for (let i = 0; i < checkOneList.length; i++) {
        let checkOne = checkOneList[i];
        checkOne.onclick = function () {
            // 判断所有的单选(商品)是否全部被选中  ?

            // 计数法   => 每次点击 遍历所有的单选 => 统计选中的元素的个数
            // var count = 0;
            // for (var j = 0; j < checkOneList.length; j++) {
            //     var item = checkOneList[j];
            //     if (item.checked) { // item.checked = true
            //         count++;
            //     }
            // }
            // // if (count == checkOneList.length) {
            // //     checkAll.checked = true;
            // // } else {
            // //     checkAll.checked = false;
            // // }

            // checkAll.checked = count == checkOneList.length ? true : false;

            // 假设法
            /* var flag = true;  // 假设全都选中
            for (var j = 0; j < checkOneList.length; j++) {
                var item = checkOneList[j];

                // !item.checked == true  => item.checked === false
                if (!item.checked) {//存在未选中的
                    flag = false;
                }
            }
            checkAll.checked = flag; */


            // every()   
            // var flag = Array.from(checkOneList).every(function (item) {
            //     return item.checked;
            // })
            // checkAll.checked = flag;

            // checkAll.checked = Array.from(checkOneList).every(function (item) {
            //     return item.checked;
            // })

            var flag = Array.from(checkOneList).every(item => item.checked);
            checkAll.checked = flag;

        }
    }
</script>

</html>